Messages in this thread Patch in this message | | | Subject | Re: [PATCH 3/3] tools lib traceevent: Introduce pevent_strerror | From | Steven Rostedt <> | Date | Tue, 12 Jun 2012 14:01:54 -0400 |
| |
On Tue, 2012-06-12 at 16:42 +0900, Namhyung Kim wrote: > From: Namhyung Kim <namhyung.kim@lge.com> > > The pevent_strerror() sets @buf to a string that describes the > (libtraceevent-specific) error condition that is passed via @errnum. > > This is similar to strerror_r() and does same thing if @errnum has a > standard errno value. > > Cc: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Steven Rostedt <rostedt@goodmis.org> > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > --- > tools/lib/traceevent/event-parse.c | 48 ++++++++++++++++++++++++++++++++++++ > tools/lib/traceevent/event-parse.h | 2 ++ > 2 files changed, 50 insertions(+) > > diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c > index 866bdca4825d..3ed2d9362e69 100644 > --- a/tools/lib/traceevent/event-parse.c > +++ b/tools/lib/traceevent/event-parse.c > @@ -4706,6 +4706,54 @@ enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf, > return ret; > } > > +/* > + * This must have a same ordering as the enum pevent_errno. > + */ > +static const char * const pevent_error_str[] = { > + "failed to allocate memory", > + "failed to parse event", > + "failed to read event id", > + "failed to read event format", > + "failed to read event print fmt", > + "failed to allocate field name for ftrace", > +}; > + > +int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum, > + char *buf, size_t buflen)
Hmm, actually I wonder if we should put the error into the pevent structure. Then we wouldn't even need to waste time to pass the data through.
That is, you can simply do:
ret = pevent_foo(); if (ret < 0) { pevent_strerr(pevent, buf, buflen); printf("%s\n", buf); }
Perhaps even include a pevent_perror(), to just do:
if (ret < 0) { pevent_perror(pevent); return ret; }
-- Steve
> +{ > + int idx; > + const char *msg; > + > + if (errnum >= 0) { > + strerror_r(errnum, buf, buflen); > + return 0; > + } > + > + if (errnum < __PEVENT_ERRNO__START || > + errnum >= __PEVENT_ERRNO__END) > + return -1; > + > + idx = errnum - __PEVENT_ERRNO__START; > + msg = pevent_error_str[idx]; > + > + switch (errnum) { > + case PEVENT_ERRNO__MEM_ALLOC_FAILED: > + case PEVENT_ERRNO__PARSE_EVENT_FAILED: > + case PEVENT_ERRNO__READ_ID_FAILED: > + case PEVENT_ERRNO__READ_FORMAT_FAILED: > + case PEVENT_ERRNO__READ_PRINT_FAILED: > + case PEVENT_ERRNO__OLD_FTRACE_ARG_FAILED: > + snprintf(buf, buflen, "%s", msg); > + break; > + > + default: > + /* cannot reach here */ > + break; > + } > + > + return 0; > +} > + > int get_field_val(struct trace_seq *s, struct format_field *field, > const char *name, struct pevent_record *record, > unsigned long long *val, int err) > diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h > index 24b7649d530b..7e90aba20850 100644 > --- a/tools/lib/traceevent/event-parse.h > +++ b/tools/lib/traceevent/event-parse.h > @@ -576,6 +576,8 @@ int pevent_data_pid(struct pevent *pevent, struct pevent_record *rec); > const char *pevent_data_comm_from_pid(struct pevent *pevent, int pid); > void pevent_event_info(struct trace_seq *s, struct event_format *event, > struct pevent_record *record); > +int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum, > + char *buf, size_t buflen); > > struct event_format **pevent_list_events(struct pevent *pevent, enum event_sort_type); > struct format_field **pevent_event_common_fields(struct event_format *event);
| |